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Auswahl der wissenschaftlichen Literatur zum Thema „AFEA“
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Zeitschriftenartikel zum Thema "AFEA"
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Mathaba, Richard Siphamandla Ryan, Nirmala Dorasamy und Kudayja Mohammed Parker. „THE EFFECTIVENESS OF EXTERNAL WHOLE-SCHOOL EVALUATION ON UNDERPERFORMING SECONDARY SCHOOLS IN THE MPUMALANGA PROVINCE“. Commonwealth Youth and Development 12, Nr. 2 (28.09.2016): 49–68. http://dx.doi.org/10.25159/1727-7140/1635.
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The study was conducted in the Mpumalanga province and focused on a sample of 18 externally evaluated underperforming secondary schools across all four districts of the province. The schools obtained an average pass rate of less than 30% in the 2011 Grade 12 examinations. The main objectives of the study were to analyse the purpose of whole-school evaluation (WSE) from a quality assurance perspective; to investigate the significance of a key component of WSE, namely assessing the quality of teaching, learning and educator development; to analyse the Grade 12 results of externally evaluated underperforming secondary schools pre- and post-evaluation; to analyse monitoring and evaluation reports for changes in teaching, learning and teacher development, as well as to identify factors impeding teaching, learning and teacher development in underperforming secondary schools. WSE is a system of evaluating the performance of schools as a whole. Corporate contribution to improve performance is measured, rather than simply the performance of individual staff members. Furthermore, WSE is one intervention to move schools that are in a critical situation along the path to becoming effective schools. Guidelines for quality assurance in education, especially at school level, are underpinned by the nine areas for evaluation (AFEs), namely basic functionality of the school (AFE1), leadership, management and communication (AFE2), governance and relationships (AFE3), quality of teaching and learning, and educator development (AFE4), curriculum provisioning and resources (AFE5), learner achievement (AFE6), school safety, security and discipline (AFE7), school infrastructure (AFE8), and parents and the community (AFE9). The mixed methods approach was used. This approach made it easy to reconcile findings through triangulation and complementing qualitative and quantitative data (both primary and secondary). The study relied on secondary data (external WSE reports and Grade 12 results), as well as primary data obtained from questionnaires administered to school management teams (SMTs) of the sampled underperforming secondary schools. The study revealed the great level of acceptance of the external WSE process by SMTs in Mpumalanga province’s underperforming secondary schools, as a means of quality assurance in order to achieve improvement. Furthermore, it revealed the extent to which improvement and development in the underperforming schools occurred as a result of the external WSE process. It was found that the results of seventeen of the 18 schools (94.4%) had improved. Furthermore, the study confi rmed that what was revealed in the external WSE as areas for development came as a revelation to SMTs. As a result, the manner in which teaching, learning and teacher development (AFE4) as a key component of WSE is viewed by teachers and SMTs, has been positively influenced.
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Briand, Anne-Laure. „2e congrès de l’Association Française d’Ethnologie et d’Anthropologie (AFEA)“. Journal des anthropologues, Nr. 144-145 (15.04.2016): 271–75. http://dx.doi.org/10.4000/jda.6454.
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Kessler, Samuel J., Funan Jiang und R. Andrew Hurley. „The State of Automated Facial Expression Analysis (AFEA) in Evaluating Consumer Packaged Beverages“. Beverages 6, Nr. 2 (21.04.2020): 27. http://dx.doi.org/10.3390/beverages6020027.
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In the late 1970s, analysis of facial expressions to unveil emotional states began to grow and flourish along with new technologies and software advances. Researchers have always been able to document what consumers do, but understanding how consumers feel at a specific moment in time is an important part of the product development puzzle. Because of this, biometric testing methods have been used in numerous studies, as researchers have worked to develop a more comprehensive understanding of consumers. Despite the many articles on automated facial expression analysis (AFEA), literature is limited in regard to food and beverage studies. There are no standards to guide researchers in setting up materials, processing data, or conducting a study, and there are few, if any, compilations of the studies that have been performed to determine whether any methodologies work better than others or what trends have been found. Through a systematic Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) review, 38 articles were found that were relevant to the research goals. The authors identified AFEA study methods that have worked and those that have not been as successful and noted any trends of particular importance. Key takeaways include a listing of commercial AFEA software, experimental methods used within the PRISMA analysis, and a comprehensive explanation of the critical methods and practices of the studies analyzed. Key information was analyzed and compared to determine effects on the study outcomes. Through analyzing the various studies, suggestions and guidance for conducting and analyzing data from AFEA experiments are discussed.
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Schiller, Devon. „The Black Box Grimaces Back“. Grimace, Vol. 2, no. 1 (2017): 72–81. http://dx.doi.org/10.47659/m2.072..art.
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With the algorithmic age of computable emotions, an increasing number of digital artists base the form of their Internet or sculptural installation on Automated Facial Expression Analysis (AFEA), and its functionality achieved via the photographic documentation in face databases. These contemporary artists make visible a digital habit of thought that objectivates the human face into a plastic grotesque of grimacing extremis, and the self inside out into the universal or utilitarian. Yet, most AFEA systems – a term little clarified and much confused with facial recognition or biometrics – are “black box” frameworks. Introduced by the technological industry and scientific experts, such proprietary closed source algorithms veil the majority of program functionality input from available data output, hiding how it works from immediate observation by artist and audience. By problematizing Julius von Bismarck’s Public Face (2008-14) and its intermedial genealogies, I probe the extent to which AFEA represents the face and its expression of emotion from a technostalgic view that reduces scientific complexity, while informing how we think about what we feel today. Keywords: automated facial expression analysis, biometrics, digital art and science, facial recognition algorithms, photography
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Schiller, Devon. „The Black Box Grimaces Back“. Grimace, Vol. 2, no. 1 (2017): 72–81. http://dx.doi.org/10.47659/m2.072.art.
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With the algorithmic age of computable emotions, an increasing number of digital artists base the form of their Internet or sculptural installation on Automated Facial Expression Analysis (AFEA), and its functionality achieved via the photographic documentation in face databases. These contemporary artists make visible a digital habit of thought that objectivates the human face into a plastic grotesque of grimacing extremis, and the self inside out into the universal or utilitarian. Yet, most AFEA systems – a term little clarified and much confused with facial recognition or biometrics – are “black box” frameworks. Introduced by the technological industry and scientific experts, such proprietary closed source algorithms veil the majority of program functionality input from available data output, hiding how it works from immediate observation by artist and audience. By problematizing Julius von Bismarck’s Public Face (2008-14) and its intermedial genealogies, I probe the extent to which AFEA represents the face and its expression of emotion from a technostalgic view that reduces scientific complexity, while informing how we think about what we feel today. Keywords: automated facial expression analysis, biometrics, digital art and science, facial recognition algorithms, photography
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Rhodes, Eric R., Andrew P. Tomaras, Glen McGillivary, Pamela L. Connerly und Luis A. Actis. „Genetic and Functional Analyses of the Actinobacillusactinomycetemcomitans AfeABCD Siderophore-Independent Iron Acquisition System“. Infection and Immunity 73, Nr. 6 (Juni 2005): 3758–63. http://dx.doi.org/10.1128/iai.73.6.3758-3763.2005.
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ABSTRACT The Actinobacillus actinomycetemcomitans afeABCD iron transport system, the expression of which is controlled by iron and Fur, was identified in three different isolates. The protein products of this locus are related to bacterial ABC transporters involved in metal transport. Transformation of the Escherichia coli 1017 iron acquisition mutant with a plasmid harboring afeABCD promoted cell growth under iron-chelated conditions. However, insertion disruption of each of the afeABCD coding regions abolished this growth-relieving effect. The replacement of the parental afeA allele with the derivative afeA::EZ::TN<KAN-2> drastically reduced the ability of A. actinomycetemcomitans cells to grow under iron-chelated conditions.
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Qian, Huaming, Yu Peng und Mei Cui. „Adaptive Observer-Based Fault-Tolerant Control Design for Uncertain Systems“. Mathematical Problems in Engineering 2015 (2015): 1–16. http://dx.doi.org/10.1155/2015/429361.
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This study focuses on the design of the robust fault-tolerant control (FTC) system based on adaptive observer for uncertain linear time invariant (LTI) systems. In order to improve robustness, rapidity, and accuracy of traditional fault estimation algorithm, an adaptive fault estimation algorithm (AFEA) using an augmented observer is presented. By utilizing a new fault estimator model, an improved AFEA based on linear matrix inequality (LMI) technique is proposed to increase the performance. Furthermore, an observer-based state feedback fault-tolerant control strategy is designed, which guarantees the stability and performance of the faulty system. Moreover, the adaptive observer and the fault-tolerant controller are designed separately, whose performance can be considered, respectively. Finally, simulation results of an aircraft application are presented to illustrate the effectiveness of the proposed design methods.
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Karvatska, M., H. Lavrenyuk, V. P. Parhomenko und B. Mykhalichko. „QUANTUM CHEMICAL SIMULATION OF THE INHIBITORY EFFECT OF AQUEOUS SOLUTIONS OF INORGANIC COPPER(II) SALTS ON THE COMBUSTION OF HYDROCARBONS“. Bulletin of Lviv State University of Life Safety 23 (30.06.2021): 33–38. http://dx.doi.org/10.32447/20784643.23.2021.05.
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Introduction. The search for chemicals that would have an effective fire extinguishing effect and the development of new fire extinguishers based on them is an extremely important problem of fire safety. It is known from the literature that new aqueous fire extinguishing agents (AFEAs) based on dissolved inorganic salts of transition metals, in particular, copper(II) chloride salts, have a rather efficient inhibitory effect on the hydrocarbon flame. However, the mechanism of inhibition of hydrocarbon combustion by this class of substances is not completely ascertained. However, it is reliable information about the processes that take place in the flame after the bringing in there of the aerosol of the mentioned AFEA will allow a systematic search for more optimal chemical composition of dissolved inorganic salts of d-metals. Purpose. The purpose of the work is to reveal the peculiarities of the interaction of concentrated aqueous solutions of copper(II) chloride salts with chemically active flame particles.Methods. Quantum chemical calculations of the chemical activity of radicals that appear in the flame and the physicochemical processes that occur in the flame after the bringing on there of AFEA aerosol.Results. The mechanism of a fire-extinguishing effect of aqueous solutions of inorganic copper(II) salts on a hydrocarbon flame is investigated by a calculation method. The sequence of stages of chemical processes that occur in the flame during the inhibiting combustion of hydrocarbons by AFEAs—concentrated solutions of CuCl2 and K2[CuCl4]—and the thermal effects of all reactions that accompany each of these stepwise transformations were ascertained. The stages of the interaction of gaseous Cu2Cl4 molecules with ×OH and ×H radicals in flame with the formation of first a radical-molecular complex and then a molecular complex are decisive in the process of inhibition and display the processes of interruption of chain reactions, i.e. deactivation of radicals in a flame.Conclusion. Thus, using the method of quantum chemical calculations the mechanism of inhibition of hydrocarbon combustion by copper(II) salts was offered. The mechanism of this process is considered to be associative, the decisive elementary act of which is carried out according to the scheme of addition of active radicals of a flame (×OH particles) to gaseous molecules Cu2Cl4 with the formation of radical-molecular complex [{Cu(×OH)Cl2}2] and with its subsequent deactivation by ×H particles.
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Wei, Qun, Hua Jiang und Cheng Shan Peng. „Study on Actual Finite Element Analysis of Steel Structure“. Applied Mechanics and Materials 501-504 (Januar 2014): 538–42. http://dx.doi.org/10.4028/www.scientific.net/amm.501-504.538.
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Due to the limitation conditions of computer hardware in the past, the structure members need to be simplified in order to save the computing resources during the finite element analysis (FEA). During FEA of Steel joints, the simplified model is considered as hinge joint, rigid joint or half-rigid joint, which is different with the actual force. With the improvement of computer technology and hardware, actual finite element analysis method (AFEA) is proposed in consider of influence of actual model, welding, plate size and bolts, which is a more acceptable method in Precision compared with last.
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Owowo, Julius, und S. Olutunde Oyadiji. „Finite element analysis and experimental measurement of acoustic wave propagation for leakage detection in an air-filled pipe“. International Journal of Structural Integrity 8, Nr. 4 (14.08.2017): 452–67. http://dx.doi.org/10.1108/ijsi-12-2015-0061.
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Purpose The purpose of this paper is to employ the acoustic wave propagation method for leakage detection in pipes. The first objective is to use acoustic finite element analysis (AFEA) method to simulate acoustic wave propagation and acoustic wave reflectometry in an intact pipe and in pipes with leaks of various sizes. This is followed by the second objective which is to validate the effectiveness and the practicability of the acoustic wave method via experimental testing. The third objective involves the decomposition and de-noising of the measured acoustic waves using stationary wavelet transform (SWT). It is shown that this approach, which is used for the first time on leakage detection in pipes, can be used to identify, locate and estimate the size of a leakage defect in a pipe. Design/methodology/approach The research work was designed inline with best practices and acceptable standards. The research methodology focusses on five basic areas: literature review; experimental measurements; simulations; data analysis and writing-up of the study with clear-cut communication of the findings. The approach used was acoustic wave propagation-based method in conjunction with SWT for leakage detection in fluid-filled pipe. Findings First, the simulation of acoustic wave propagation and acoustic wave reflectometry in fluid-filled pipes with and without leakage have great potential in leakage detection in pipeline systems and can detect very small leaks of 1 mm diameter. Second, the measured noise-contaminated acoustic wave propagation in a fluid-filled pipe can be successfully de-noised using the SWT method in order to clearly identify and locate leakage as little as 5 mm diameter in a pipe. Third, AFEA of a fluid-filled pipe can be achieved with the simulation of only the fluid content of the pipe and without the inclusion of the pipe in the model. This eliminates contact interaction of the solid pipe walls and the fluid, and as a consequence reduces computational time and resources. Fourth, the relationship of the ratio of the leakage diameter to the ratio of the first and second secondary wave amplitudes caused by the leakage can be represented by a second-order polynomial function. Fifth, the identification of leakage in a pipe is intuitive from mere comparison of the acoustic waveforms of an intact pipe with that of a pipe with a leakage. Originality/value The research work is a novelty and was developed from the scratch. The AFEA of acoustic wave propagation and acoustic wave reflectometry in a static fluid-filled pipe, and the SWT method have been used for the first time to detect, locate and estimate the size of a leakage in a fluid-filled pipe.
Dissertationen zum Thema "AFEA"
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Bari, Mahdi. „A finite element study of shell and solid element performance in crash-box simulations“. Thesis, Högskolan Väst, Avdelningen för maskinteknik och naturvetenskap, 2015. http://urn.kb.se/resolve?urn=urn:nbn:se:hv:diva-7575.
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This thesis comprehends a series of nonlinear numerical studies with the finite element software's LS-Dyna and Impetus AFEA. The main focus lies on a comparative crash analysis of an aluminium beam profile which the company Sapa technology has used during their crash analysis. The aluminium profile has the characteristic of having different thickness over span ratios within the profile. This characteristic provided the opportunity to conduct a performance investigation of shell and solid elements with finite element analysis. Numerical comparisons were made between shell and solid elements where measurable parameters such as internal energy, simulation times, buckling patterns and material failures were compared to physical tests conducted prior to this thesis by Sapa technology. The performance investigation of shell and solid elements was initiated by creating models of the aluminium profile for general visualization and to facilitate the meshing of surfaces. The meshing procedure was considered to be an important factor of the analysis. The mesh quality and element orientations were carefully monitored in order to achieve acceptable results when the models were compared to physical tests. Preliminary simulations were further conducted in order to obtain a clear understanding of software parameters when performing crash simulations in LS-Dyna and Impetus AFEA. The investigated parameters were element formulations and material models. A general parameter understanding facilitated in the selection of parameters for actual simulations, where material failure and damage models were used. In conclusion, LS-Dyna was observed to provide a bigger internal energy absorption during the crushing of the beam with longer simulation times for solid elements when compared to shell elements. Impetus AFEA did on the other hand provide results close to physical test data with acceptable simulation times when compared to physical tests. The result difference obtained from the FE-software's in relation to physical crash experiments were considered to be varied but did indicate that shell elements were efficient enough for the specific profile during simulations with LS-Dyna. Impetus AFEA proved that the same time to be numerically efficient for energy approximations with solid elements refined with the third polynomial.
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Tribe, Anthony Henry Fead. „The names of wisdom : a critical edition and annotated translation of chapters 1-5 of Vilasavajra's commentary on the Namasamgiti, with introduction and textual notes“. Thesis, University of Oxford, 1994. http://ora.ox.ac.uk/objects/uuid:29da9a3b-ab9a-4cb4-afea-dd3160be3d3f.
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The Nāmamantrārthāvalokinī ('An Explanation of the Meaning of the Namemantras') is an early, and major, commentary on the Nāmasaṃgīti ('The Chanting of Names'). Written by the eighth century Indian ācārya Vilāsavajra, it survives in the original Sanskrit and in Tibetan translation. The Nāmasamgīti enumerates the 'Names' of Mañjuśrī, the Mahayana figure embodying wisdom, and it exerted a strong influence on liturgy, ritual and meditation in the later phase of Buddhism in India (750-1200 CE). Vilāsavajra's commentary is written from a Yogācāra perspective and interprets the 'Names' within an elaborate ritual framework which consists in a maṇḍala that has Mañjuśrī as its central deity. The central part of the thesis comprises a critical edition and annotated translation of the Sanskrit text of the first five chapters of Vilāsavajra's commentary, approximately a quarter of the whole. The critical edition is based on eight Nepalese manuscripts for which a stemma codicum is established. Two blockprint editions of the Tibetan translation are consulted at cruces in the Sanskrit. Their readings, treated as those of any other witness, are incorporated into the apparatus as appropriate. The edition is followed by textual notes. Introductory material is divided into two parts. Matters relating to the Sanskrit and Tibetan materials are discussed in a section placed before the edition. These include a description of the manuscripts, discussion of the method of editing, establishment of the stemma codicum and an assessment of the Tibetan translation. An introduction to the contents precedes the translation and is primarily concerned with an outline of the ritual structure of the commentary, giving particular attention to chapters 1-5. Evidence concerning the life and date of Vilāsavajra is considered, suggesting he should be placed in the latter part of the eighth century. Assessing the work's significance for the study of Buddhism, 1 suggest that it is of historical importance in that it throws light on the process by which Tantric methods were being related to soteriology in this period; and that it contains material, especially in the sādhana of chapter 4, that contributes to an understanding of the development of Tantric forms of Buddhist meditation. The work is also the only known instance of a commentary of a Yogatantra type that survives in Sanskrit.
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de, Noronha Luke. „Deporting 'Black Britons' : portraits of deportation to Jamaica“. Thesis, University of Oxford, 2018. http://ora.ox.ac.uk/objects/uuid:80610ce1-339a-42ec-afea-7d627a1d410b.
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This thesis explores the life stories of four men who were deported from the UK to Jamaica following interaction with the criminal justice system. All four men, having moved as children, spent roughly half of their lives in the UK. For each of the men, deportation was lived as exile from home - from parents, partners, children and friends - and the thesis provides portraits of their lives in the UK and in Jamaica. In particular, it examines processes of criminalisation, illegalisation and racialisation as they interact to construct deportable subjects. This thesis asks what these life stories can tell us about the relationship between immigration control and racism. Fieldwork was conducted in Jamaica with deported persons, and in the UK with friends and family members. As such, this is an ethnography of absences and disjunctures. In the ethnographic portraits, themes of illegality, culture, gender, police racism, citizenship, and the legal construction of family life emerge, and reading the portraits together provides a rich account of racism in multi-status Britain. Ultimately, the thesis argues that immigration controls reconfigure race in the present. Moving from the UK to Jamaica, the thesis argues that borders produce racial meanings at local, national and global scales, because racial hierarchy is intimately connected to citizenship regimes and the differential mobilities they organise. Examining the racial work that borders do provides a historically specific account of race and racism, and one which centres the state. The thesis argues that even the most local of encounters, played out in particular lives, in specific times and places, are connected to the ordering of space, mobility and population through border regimes. It also argues that when challenging citizenship and border regimes, it is essential that we find new ways to theorise kinship. Based on detailed ethnographic portraits, this thesis provides a wide-ranging intervention into studies of race, migration and citizenship.
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Pilkington, Rachel. „Multi-dimensional metallochromophores with nonlinear optical properties“. Thesis, University of Manchester, 2015. https://www.research.manchester.ac.uk/portal/en/theses/multidimensional-metallochromophores-with-nonlinear-optical-properties(f3ed6a41-6c7c-457f-afea-ef81f93bfef2).html.
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New mono-chelate complexes with ferrocenyl (Fc), octamethylferrocenyl (Me8Fc) and diaminophenyl (Dap) donor groups, connected through a conjugated bridge, to ZnCl2, Zn(OAc)2 or ReCl(CO)3 acceptor groups, are described. A thorough characterisation of the complexes is provided, including single crystal structures for one pro-ligand and three complexes. Visible d(FeII)→π* metal-to-ligand charge-transfer (MLCT) bands accompany π→π* intraligand charge-transfer absorptions in the UV region. TD-DFT calculations confirm the nature of these absorptions and indicate transitions at higher energies also contain some d(FeII)→π* character. Fc and Me8Fc containing chromophores display a fully reversible oxidation process when probed electrochemically. Molecular quadratic nonlinear optical (NLO) responses are determined using hyper-Rayleigh scattering (HRS) and Stark spectroscopy. Larger β values are determined for complexes with Dap donors and ReICl(CO)3 acceptors. A family of novel fac-ReI(Lax)(CO)3(N-N) complexes, where N-N is 4,4′-dicyano-2,2′-bipyridyl (dcnbpy) or 4,4′-bis-(p-cyanophenyl)-2,2′-bipyridine (bbnbpy), with various axial ligands (Lax) are reported. The ReI complexes are useful precursors for metalation with electron-rich RuII ammine donor groups, to prepare novel tri-metallic V-shaped molecules. Single crystal X-ray structures are reported for five ReI complexes, confirming the fac geometry of the carbonyl ligands; the ReI complexes also display stretching frequencies typical of fac-ReI(Lax)(CO)3(N-N) complexes. The UV-visible spectra contain a low intensity band due to a d(ReI)→π*(bpy) transition, along with a more intense π→π* band. 1H NMR studies reveal the formation of trimetallic complexes, upon treatment of ReI complexes with a molar excess of [RuII(NH3)5(H2O)][PF6]2.The synthesis of octupolar heptametallic complexes containing RuII ammine donor groups has been investigated. The ligand 4,4′-bis-[(E)-2-(4-cyanophenyl)ethenyl]-2,2′-bipyridine (bbnpe) was used to prepare tris-chelate complexes of various transition metals, in order to understand its complexation behaviour. The ZnII tris-chelate BPh4– salt was treated with a 10 molar excess of a RuII ammine aquo complex, to produce the heptametallic complex as a mixed anion salt. HRS and Stark spectroscopy have been used to determine the quadratic NLO response for the heptametallic mixed anion complex salts, the latter gives large β0 values, approximately 10–27 esu. Density functional theory (DFT) calculations have been carried out on twelve cationic, 2D NLO chromophores with pyrazinylbis(pyridinium) electron acceptors with either 4-(methoxy/dimethylamino)-phenyl or pyridyl coordinated {RuII(NH3)5}2+/trans-{RuII(NH3)4(py)}2+ electron donor groups and the results compared with data previously obtained experimentally. The B3LYP/6-311G(d) level of theory was used to model the absorption spectra and to calculate static hyperpolarisability (β0) values, whilst the B3LYP/LANL2DZ/6-311G(d) level was used for the complexes. The extent of prediction of trends in ICT bands and β0 is partial, with the main discrepancies relating to the progression from one to two electron donor groups. The quantitative accuracy of predictions diminishes as the systems depart from a relatively simple one-dimensional (1D) dipolar motif.
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Duarte, Camila Silveira. „Afec??es e paisagens in transit: processos de desterritorializa??o/reterritorializa??o e deslocamentos po?ticos nas obras da artista afeg? Lida Abdul“. PROGRAMA DE P?S-GRADUA??O EM ARTES C?NICAS, 2017. https://repositorio.ufrn.br/jspui/handle/123456789/23719.
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Coordena??o de Aperfei?oamento de Pessoal de N?vel Superior (CAPES)
Esta pesquisa tem como intuito apresentar uma reflex?o acerca da trajet?ria art?stico-biogr?fica da artista afeg? Lida Abdul (1973), a partir da an?lise de tr?s de suas obras: ?In Transit? (2008), ?Military / Body? (2004) e ?Global Porn? (2002), nas quais levanta quest?es e aborda temas sobre interven??es art?sticas em territ?rios de conflito, rela??es entre corpo e viol?ncia, e reflex?es sobre a dial?tica entre o sistema capitalista e performances pol?ticas, respectivamente. Tamb?m ser?o discutidos, em conson?ncia com as obras da artista, os conceitos de desterritorializa??o e reterritorializa??o, identidades m?veis, e fronteiras perme?veis entre as linguagens art?sticas, tendo como objeto direto para esse di?logo: a Performance Art.
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Ward, Helen. „Energy, water and carbon fluxes in the suburban environment“. Thesis, King's College London (University of London), 2013. https://kclpure.kcl.ac.uk/portal/en/theses/energy-water-and-carbon-fluxes-in-the-suburban-environment(26a95185-3af3-4c4a-afea-c9f769e93de2).html.
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To better understand boundary layer processes and improve hydro-meteorological models it is essential to quantify contributions from different land surface types to the total energy exchange. The effects of urban areas must be represented not only within densely populated towns and cities, but also at the regional scale. A multi-scale field campaign designed to investigate the exchange of energy and mass over suburban land surfaces was undertaken in Swindon, UK. Observations of heat, water vapour and carbon dioxide fluxes suggest Swindon behaves much like a natural landscape during summer, whereas anthropogenic activities dominate in winter. Eddy covariance data collected exhibit broad trends that are in accordance with studies in other locations, whilst marked seasonal contrasts build a more complete picture of the suburban environment. Scintillometry, a ground-based remote sensing technique, estimates turbulent heat fluxes at larger scales (0.1-10 km), comparable to model grids. The conventional single-wavelength method provides the sensible heat flux. Additionally, use of a unique millimetre-wave scintillometer in conjunction with an infrared scintillometer enabled both sensible and latent heat fluxes to be determined. These results represent the first observations of large-scale evaporation over urban areas using scintillometry. The technique is shown to perform reasonably well and recommendations are made for future research. Advantages include spatially integrated fluxes, particularly useful over heterogeneous surfaces where a mosaic of different land cover characteristics can lead to contrasts in surface-atmosphere exchanges. These observations are used to investigate the controls on evaporation and the behaviour of fluxes at different scales. Particular attention is given to seasonal variability, land cover and the availability of surface moisture and energy. Rapid evaporation directly after rainfall and dew are also explored. With improved understanding of the suburban climate, more accurate predictions can be made regarding the impact of land use development, environmental management schemes and climate change.
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Hutchens, Chris. „An integrated design strategy for a range of industrial electronic pressure instrumentation“. Thesis, University of South Wales, 1999. https://pure.southwales.ac.uk/en/studentthesis/an-integrated-design-strategy-for-a-range-of-industrial-electronic-pressure-instrumentation(604926cd-cf70-4281-afea-f64b05ab8161).html.
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This portfolio details the design, construction and testing of three high accuracy digital pressure indicators. A discussion of old and contemporary pressure measurement technologies is included, as well as a comprehensive market survey of electronic pressure measurement instruments currently available. An integrated design strategy is adopted for the three separate digital pressure instruments, namely a battery - powered stand alone unit, a retransmitting version and an intrinsically safe version of the battery powered unit. Their implementation takes into account many design issues including ease of manufacturing, low power circuit design and electromagnetic compatibility. Novel features available upon all three instruments resulting from the design strategy adopted are high accuracy measurements, typically ±0.2% of full scale, a battery life of over 12 months, push button zeroing and linearisation, electromagnetic compliance with minimum design changes and an intrinsically safe power supply design that may be used not only in the instrument for which it was designed but for future instruments. Individual design issues with respect to each instrument are in the three project sections which complete this portfolio.
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Niyomsuk, Orachat. „ASEAN Free Trade Area (AFTA) : how far have we come? : analysis and evidence on effects of AFTA“. Thesis, University of St Andrews, 2013. http://hdl.handle.net/10023/4475.
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This thesis addresses issues concerning trade effects of a particular RTA: AFTA. In the first part of the thesis, 2 different but related gravity frameworks are constructed as to evaluate the independent effects of AFTA on relevant countries' trade flows. The first paper proposes examining ‘AFTA-effects' on members' trade, specifically within the AFTA context. This aims to distinguish trade effects that AFTA has had on early and delayed members' trading patterns. The panel ‘Gravity Model' is constructed, pointing to control for several biases commonly observed in the cross-section model. Although the result implies that early members do share trade benefits from AFTA more than non-members, the overall ‘AFTA-effects' on the membership's trade have not been benign. Another paper measures ‘AFTA-effects' on both members' and non-members' trade. This aims to assess whether AFTA has played a role as an export base for the international market. In this case, ‘AFTA-effects' appeared positive. Such effects are driven by an enhancement in extra-export bias, suggesting that the membership's exports to outside destinations have increased post-AFTA. The last paper provides a theoretical framework addressing the incidence of RTA-membership expansion. The fact that AFTA was gradually established and empirical results indicating AFTA's impacts on members and non-members brings about the idea that bloc-membership expansion could plausibly be explained by the economic effects that these countries have received. The corollaries of trading with/without RTA-membership of a potential member's gains of trade and welfare levels are related to the decision towards membership. Even though welfare effects are not always greater, the RTA-membership status surely benefits member countries in gains from trade more than non-members. This can be perceived as one of the important reasons to explain the widespread regionalism worldwide and why joining the RTA is often seen as a safe haven strategy for a country.
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Kriel, Yusra. „The immune-modulating activity of Artemisia afra“. Thesis, University of the Western Cape, 2010. http://etd.uwc.ac.za/index.php?module=etd&action=viewtitle&id=gen8Srv25Nme4_4025_1299669473.
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This study shows that herbs can be effectively screened for potiential bio-activity using in vitro methods. Further studies will be needed to better explore Artemisia afra&rsquo
s effect on immunoregulation, particularly long term effects of the herb on the immune system and its effect on other disease states.
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Fulmaka, Aviwe. „Investigating soil microbial interactions of Portulacaria afra“. Thesis, Rhodes University, 2016. http://hdl.handle.net/10962/54598.
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Portulacaria afra commonly known as Spekboom contributes significantly to carbon sequestration and has been widely planted in degraded areas of the Eastern Cape. Approximately 50% of planted cuttings do not survive although the cause of this decline is unknown. Like many indigenous plants, Spekboom forms a symbiotic relationship with mycorrhizal fungi and the interaction with rhizobacteria may enhance and improve plant growth and establishment. This study aims to investigate these relationships which will include a survey of the arbuscular mycorrhizal (AM) fungal populations associated with Spekboom, determination of the causal agent of Spekboom decline, isolation and identification of the associated rhizobacteria and investigation of their plant growth promotion properties and assessing the ability of arbuscular mycorrhizal fungi and selected rhizobacteria to enhance establishment and growth of Spekboom. Soil and root samples from selected trial sites were used to assess AM fungal spore abundance and colonisation; isolation, characterization, and identification of rhizobacteria and determine the interaction of the microbes on Spekboom growth and tolerance to Fusarium. AM spore abundance and percentage root colonisation did not differ between the three Spekboom plots. Molecular analyses of the SSU region from the plots showed 4 families of AM fungi and were identified as Ambisporaceae, Glomeraceae, Claroideoglomeraceae and Paraglomeraceae. A suspected Fusarium pathogen was isolated and molecularly identified. Pathogenicity tests indicated reduced Spekboom growth with poor root development. Thirty four rhizobacterial isolates were tested for various plant growth promoting abilities. Of these, 6 were able to produce IAA which may promote plant root growth, 27 siderophores and 23 were phosphate solubilisers. Bacterial isolates were molecularly identified to be from various species of Bacillus, with some Arthrobacter, Enterobacter, Pseudomonas and Microbacterium. Inoculation of Spekboom cuttings with mycorrhizal fungi and selected rhizobacterial isolates significantly improved shoot height. Spekboom cuttings challenged with Fusarium and inoculated with mycorrhizal fungi and two rhizobacterial isolates significantly improved growth. The inoculation of cuttings in the nursery with mycorrhizal fungi and selected rhizobacteria is recommended prior to establishing Spekboom in the field.
Bücher zum Thema "AFEA"
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Nikolaĭ, Khristov, Hrsg. Afera. Sofii︠a︡: UI "Sv. Kliment Okhridski", 2007.
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Afera. Beograd: NIRO "Književne novine", 1986.
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L' afer. Barcelona: Edicions 62, 1998.
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Afera Pahomije. Vranje: Vranjske knjige, 2004.
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Leonov, Nikolaĭ. Idealʹnai︠a︡ afera. Moskva: ĖKSMO, 2004.
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Butt, Muhammad Younas. Afra tafri. Lahore: Sang-e-Meel, 2000.
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Afet okulu. Kavacık, İstanbul: Truva Yayınları, 2011.
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Layer-Sarzotti, Magdalena. Afera Kolekcjonera. Warszawa: Mazowieckie Centrum Kultury i Sztuki, 2011.
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Warzecha, Jaroslaw. Afera Zyrardowska. Lodz: Krajowa Agencja Wyd., 1986.
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Afera Medenica. Beograd: Partizanska knjiga, 1985.
Den vollen Inhalt der Quelle findenBuchteile zum Thema "AFEA"
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Lagouanère, Jérôme. „Tertullien et la littérature chrétienne d’Afrique: problématiques et enjeux“. In Tertullianus Afer, 9–17. Turnhout: Brepols Publishers, 2015. http://dx.doi.org/10.1484/m.ipm-eb.4.00002.
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Mattei, Paul. „Aspects de l’influence de Tertullien sur le développement des doctrines trinitaire et christologique dans la patristique latine“. In Tertullianus Afer, 21–41. Turnhout: Brepols Publishers, 2015. http://dx.doi.org/10.1484/m.ipm-eb.4.00003.
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Kitzler, Petr. „Tertullian’s Concept of the Soul and His Corporealistic Ontology“. In Tertullianus Afer, 43–62. Turnhout: Brepols Publishers, 2015. http://dx.doi.org/10.1484/m.ipm-eb.4.00004.
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Zocca, Elena. „Tertullien et le donatisme : quelques remarques“. In Tertullianus Afer, 63–104. Turnhout: Brepols Publishers, 2015. http://dx.doi.org/10.1484/m.ipm-eb.4.00005.
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Fialon, Sabine. „Semen est sanguis christianorum (Apol. 50, 13). Tertullien et l’hagiographie africaine (iie-vie siècles)“. In Tertullianus Afer, 105–38. Turnhout: Brepols Publishers, 2015. http://dx.doi.org/10.1484/m.ipm-eb.4.00006.
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Ciccolini, Laetitia. „Tertullianus magister : Tertullien lu par Cyprien de Carthage“. In Tertullianus Afer, 141–66. Turnhout: Brepols Publishers, 2015. http://dx.doi.org/10.1484/m.ipm-eb.4.00007.
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Colot, Blandine. „Africain, romain et chrétien : l’engagement religieux de Tertullien et de Lactance, chacun en son époque“. In Tertullianus Afer, 167–84. Turnhout: Brepols Publishers, 2015. http://dx.doi.org/10.1484/m.ipm-eb.4.00008.
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Freund, Stefan. „Tertullian bei Laktanz“. In Tertullianus Afer, 185–203. Turnhout: Brepols Publishers, 2015. http://dx.doi.org/10.1484/m.ipm-eb.4.00009.
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Mellerin, Laurence. „De Tertullien à Augustin, vers une définition de l’irrémissible“. In Tertullianus Afer, 205–30. Turnhout: Brepols Publishers, 2015. http://dx.doi.org/10.1484/m.ipm-eb.4.00010.
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Lagouanère, Jérôme. „Augustin, lecteur critique du De anima de Tertullien“. In Tertullianus Afer, 231–58. Turnhout: Brepols Publishers, 2015. http://dx.doi.org/10.1484/m.ipm-eb.4.00011.
Der volle Inhalt der QuelleKonferenzberichte zum Thema "AFEA"
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Liu, Zhengchun, Robello Samuel, Adolfo Gonzales und Yongfeng Kang. „Sequential Annular Fluid Expansion Analysis for Wellbore Completion Design“. In ASME 2020 39th International Conference on Ocean, Offshore and Arctic Engineering. American Society of Mechanical Engineers, 2020. http://dx.doi.org/10.1115/omae2020-18851.
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Abstract Annular fluid expansion analysis (AFEA) is a vital step when designing an oil/gas well or geothermal well. Traditionally, an AFEA is performed between a drilling operation (initial condition) and a production operation (final condition). However, well design engineers desire to perform an AFEA between any two operations. The objective of this work is to address that challenge. Sequential AFEA refers to the procedure in which output data (e.g., fluid volume change) of one AFEA are used as input data for another AFEA; the underlying operations are “sequential”. As a result, an AFEA can be configured between any two operations, provided that the “initial condition” operation is before the “final condition” operation. This two-pass AFEA model has been implemented in computer programs and has been integrated with a commercial software tool, including a wellbore thermal flow simulator and tubular stress analyzer. Offshore well examples were used to validate the model. Case study results indicate that a sequential AFEA is in good agreement with a traditional one-pass AFEA in terms of both forward and backward operation sequences.
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Shim, D. J., S. Kalyanam, E. Punch, T. Zhang, F. Brust, G. Wilkowski, A. Goodfellow und M. Smith. „Advanced Finite Element Analysis (AFEA) Evaluation for Circumferential and Axial PWSCC Defects“. In ASME 2010 Pressure Vessels and Piping Division/K-PVP Conference. ASMEDC, 2010. http://dx.doi.org/10.1115/pvp2010-25162.
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The Advanced Finite Element Analysis (AFEA) methodology has been developed by the US NRC and the nuclear industry to evaluate the natural crack growth of primary water stress corrosion cracking (PWSCC) in nickel-based alloy materials. The AFEA methodology allows the progression of a planar crack subjected to typical SCC-type growth laws by calculating stress intensity factors at every nodal point along the crack front, and incrementally advancing the crack front in a more natural manner. This paper describes the enhancements that have been made to the existing AFEA methodology. The most significant enhancement was the feature to evaluate axial crack growth where the crack was contained within the susceptible material. In this paper, this methodology was validated by performing an AFEA evaluation for the axial crack that was found in the V.C. Summer hot leg dissimilar metal weld. Other enhancements to the AFEA methodology include; upgrade to the PipeFracCAE© software developed by Engineering Mechanics Corporation of Columbus, feature to handle non-idealized circumferential through-wall cracks, mapping of weld residual stress for crack growth, and determination of limiting crack size using elastic-plastic J-integral analysis that included secondary stress (weld residual stress and thermal transient stress) effects.
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Rudland, D., D. J. Shim und A. Csontos. „Natural Flaw Shape Development Due to Stress Corrosion Cracking“. In ASME 2008 Pressure Vessels and Piping Conference. ASMEDC, 2008. http://dx.doi.org/10.1115/pvp2008-61205.
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Typical ASME Section XI subcritical cracking analyses assume an idealized flaw shape driven by stress intensity factors developed for semi-elliptical shaped flaws. Recent advanced finite element analyses (AFEA) conducted by both the US NRC and the nuclear industry for long circumferential indications found in the pressurizer nozzle dissimilar metal welds at the Wolf Creek power plant, suggest that the semi-elliptical flaw assumption may be overly conservative in some cases. The AFEA methodology that was developed allowed the progression of a planar flaw subjected to typical SCC-type growth laws by calculating stress intensity factors at every nodal point along the crack front, and incrementally advancing the crack front in a more natural manner. Typically crack growth analyses increment the semi-elliptical flaw by considering only the stress intensity factor at the deepest and surface locations along the crack front, while keeping the flaw shape semi-elliptical. In this paper, a brief background to the AFEA methodology and the analyses conducted in the Wolf Creek effort will be discussed. In addition, the natural behavior of surface cracks under normal operating conditions (plus welding residual stress) will be investigated and compared to the semi-elliptical assumption. Conclusions on the observation of when semi-elliptical flaw assumptions are appropriate will be made. These observations will add insight into the conservatism of using an idealized flaw shape assumption.
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Rudland, D., D. J. Shim und S. Xu. „Simulating Natural Axial Crack Growth in Dissimilar Metal Welds due to Primary Water Stress Corrosion Cracking“. In ASME 2013 Pressure Vessels and Piping Conference. American Society of Mechanical Engineers, 2013. http://dx.doi.org/10.1115/pvp2013-97188.
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For axial subcritical crack growth in dissimilar metal (DM) welds due to Primary Water Stress Corrosion Cracking (PWSCC), the crack growth in the length direction is limited to the weld width since the base materials are not susceptible to this type of cracking mechanism. However, the crack may continue to grow in the depth direction until it penetrates the wall thickness. Since the weld width can be much less than the pipe wall thickness, axial cracks have the potential of growing much deeper than they are long. Published stress intensity factor influence functions for semi-elliptical axial cracks in pipe suggest that as the half crack length (c) becomes smaller than the crack depth (a), the stress intensity factor at the deepest point of the crack begins to decrease. These solutions suggest that in many cases, these types of cracks may arrest before penetrating the wall thickness. However, natural flaw growth using the Advanced Finite Element Method (AFEA) suggests that these cracks will not arrest and the stress intensity factor does not decrease in a manner suggested by idealized flaw growth analyses using semi-elliptical crack influence functions. In this paper, modifications to idealized flaw growth analyses are proposed to predict the natural PWSCC axial crack growth within DM welds. A series of modified flaw growth predictions are presented and compared to published AFEA results. The simplistic rules developed in the paper allow the use of standard influence functions in predicting the time to leakage for axial cracks in DM welds without having to conduct the more complex AFEA analyses.
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Kristoffersen, Martin, Tore Børvik und Lars Olovsson. „Pipeline Fracture due to Compression-Tension Loading Caused by Foreign Object Impact“. In ASME 2018 37th International Conference on Ocean, Offshore and Arctic Engineering. American Society of Mechanical Engineers, 2018. http://dx.doi.org/10.1115/omae2018-77964.
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In areas frequented by fishing vessels, trawl equipment or anchors may interfere with pipelines and cause damage through impact, potential hooking, and ensuing release of the pipeline. This load sequence of denting followed by global bending and springback results in a complex stress and strain history. Experiments have shown that fracture in an impacted pipe typically arises along the bottom of the dent, where the material suffers high compressive strains in the impact and hooking phase, and a rapid change to tension during the rebound phase. High compressive strains may reduce the strain to failure significantly for a succeeding tensile phase. A common trait of ductile damage models is to account for damage through nucleation, growth and coalescence of voids, which traditionally is thought to occur during tension. In this study, an uncoupled phenomenological Cockcroft-Latham-type fracture model accounting for anisotropic damage is used. The fracture model is implemented in the explicit finite element programme IMPETUS Afea Solver, and calibrated using material tests. Simulations show that the proposed fracture model is able to account for the observed behaviour.
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Limido, Jérôme, Christian Puillet und Jean-Paul Vila. „Explosion of hydrazine tanks due to space debris impacts“. In 2019 15th Hypervelocity Impact Symposium. American Society of Mechanical Engineers, 2019. http://dx.doi.org/10.1115/hvis2019-099.
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Abstract The impact of space debris on a spacecraft can result in a catastrophic event that not only destroys the structure but can also create more space debris. The design of any spacecraft requires understanding the potential damage that can be inflicted by such an event. We consider the case of a satellite hydrazine fuel tank and the consequences of a hypervelocity impact from space debris. The purpose of this study is to better understand the mechanisms of detonation of hydrazine vapor during a hypervelocity impact on a low-pressure reservoir. The IMPETUS Afea Solver® and Explo5 software were used to perform numerical simulations of operational impact configurations (v = 14 km / s). The multi-scale calculations are performed using the Next Generation IMPETUS ɣSPH solver. A numerical assessment of the impact performance at the scale of the reactive fluid reservoir representative of a real configuration (global and local scale) was carried out. The model includes the detonation in the fluid and the transfer of the momentum to the structure which includes capturing the perforation of the structure that results from the explosive loading. A first diagram (impact velocity, diameter / perforation-explosion) was constructed on a reference tank of diameter 50cm and thickness 1mm in titanium.
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Shim, Do-Jun, David Rudland und David Harris. „Modeling of Subcritical Crack Growth due to Stress Corrosion Cracking: Transition From Surface Crack to Through-Wall Crack“. In ASME 2011 Pressure Vessels and Piping Conference. ASMEDC, 2011. http://dx.doi.org/10.1115/pvp2011-57267.
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Recent work conducted using the Advanced Finite Element Analysis (AFEA) method to simulate the ‘natural’ crack growth of a circumferential PWSCC demonstrated that a subcritical surface crack can transition to a through-wall crack with significant differences between the inner diameter and outer diameter crack lengths. In the current version of the xLPR (Extremely Low Probability of Rupture) code, once the surface crack penetrates the wall thickness, an idealized through-wall crack (which has an equivalent area as the final surface crack) is formed. This type of crack transition was selected since no general stress intensity factor (K) solutions were available for crack shapes that would form during the transitioning stages, i.e., non-idealized or slanted through-wall cracks. However, during the pilot study of the xLPR code, it has been identified that this crack transition method may provide non-conservative results in terms of leak-rate calculations. In this paper, in order to compare the ‘natural’ versus ‘idealized’ crack transition behavior, limited example cases were considered where both crack transitions were simulated using 3D finite element analyses. In addition, leak-rate calculations were performed to study how the two different crack transition methods can affect the leak-rates. The results of the present study demonstrate that the ‘idealized’ transition from surface to through-wall crack can significantly affect the leak-rate calculations.
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Limido, Jérôme, Mohamed Trabia, Shawoon Roy, Brendan O’Toole, Richard Jennings, Wayne L. Mindle, Michael Pena, Edward Daykin, Robert Hixson und Melissa Matthes. „Modeling of Hypervelocity Impact Experiments Using Gamma-SPH Technique“. In ASME 2017 Pressure Vessels and Piping Conference. American Society of Mechanical Engineers, 2017. http://dx.doi.org/10.1115/pvp2017-65517.
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A series of experiments were performed to study plastic deformation of metallic plates under hypervelocity impact at the University of Nevada, Las Vegas (UNLV) Center for Materials and Structures using a two-stage light gas gun. In these experiments, cylindrical Lexan projectiles were fired at A36 steel target plates with velocities range of 4.5–6.0 km/s. Experiments were designed to produce a front side impact crater and a permanent bulging deformation on the back surface of the target without inducing complete perforation of the plates. Free surface velocities from the back surface of target plate were measured using the newly developed Multiplexed Photonic Doppler Velocimetry (MPDV) system. To simulate the experiments, a Lagrangian-based smooth particle hydrodynamics (SPH) is typically used to avoid the problems associated with mesh instability. Despite their intrinsic capability for simulation of violent impacts, particle methods have a few drawbacks that may considerably affect their accuracy and performance including, lack of interpolation completeness, tensile instability, and existence of spurious pressure. Moreover, computational time is also a strong limitation that often necessitates the use of reduced 2D axisymmetric models. To address these shortcomings, IMPETUS Afea Solver® implemented a newly developed SPH formulation that can solve the problems regarding spurious pressures and tensile instability. The algorithm takes full advantage of GPU Technology for parallelization of the computation and opens the door for running large 3D models (20,000,000 particles). The combination of accurate algorithms and drastically reduced computation time now makes it possible to run a high fidelity hypervelocity impact model.
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Hayashi, T., S. F. Hankinson, T. Saito, C. K. Ng und W. H. Bamford. „Flaw Evaluation for PWR and BWR Component Weld Joints Using Advanced FEA Modeling Techniques“. In ASME 2009 Pressure Vessels and Piping Conference. ASMEDC, 2009. http://dx.doi.org/10.1115/pvp2009-77855.
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Primary Water Stress Corrosion Cracking (PWSCC) of Pressurized Water Reactor (PWR) primary loop piping/nozzle Dissimilar Metal Weld (DMW) joints and Inter Granular Stress Corrosion Cracking (IGSCC) of Boiling Water Reactor (BWR) weld joints is an ongoing issue in the nuclear power industry. Recent field experiences with PWSCC of various DMW joints in US plants led to the development and application of an Advanced Finite Element Analyses (AFEA) methodology that permits crack propagation with a natural flaw shape. Crack growth and fracture evaluations for both PWR and BWR components are generally performed based on a conservative, idealized crack shape model, e.g. semi-ellipse, rectangle, etc., depending on the geometry of the crack and the component. Conventional evaluation methodologies and/or assumptions of this kind, in some cases may provide excessive conservatisms. The use of natural flaw shape development with crack propagation might provide a more realistic assessment of crack growth and structural integrity. The prime purpose of this study is to demonstrate the conservatism/margins in the conventional “idealized crack shape” methodology. A comparison study of crack growth behavior between the applications of the idealized and natural crack shape methodologies has been performed in order to assess the level of conservatism/margins in the conventional crack growth evaluation methodology and the possible impacts on the structural integrity evaluation for both PWR and BWR components. Comparison studies on the impacts of the differences in crack growth law and loading condition used for crack growth evaluations have been performed as well.
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Tang, Xinxin, und Hallvard G. Fjær. „Integrated Forming, Welding and Crash Simulations for an Aluminum Crash Management System“. In ASME 2015 International Design Engineering Technical Conferences and Computers and Information in Engineering Conference. American Society of Mechanical Engineers, 2015. http://dx.doi.org/10.1115/detc2015-46088.
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Simulations of production by forming and welding, and crash testing of an aluminum crash management system have been carried out. A numerical tool/interface is also developed for modeling, simulating and evaluating the material flow, the design concepts and fabrication processes continually, accurately and fast. In the present paper, the fabrication processes of the Audi A1 crash management system are studied. The system consists of a stretch-bent extruded beam, a towing nut, two extruded crash tubes and two plates that are welded together. In order to perform analyses efficiently, this study employed a common set of solid elements for modeling the forming, welding and crash processes. The forming simulation has been performed in IMPETUS Afea Solver. The solid elements have been transferred flexible from coarse single order elements into the fine higher order elements in different stages of the design. In this way, it is possible to quickly capture the key concepts of the tool design, and to ensure that the details of the product and the requirements of the tooling can be correctly predicted. The welding simulation has been performed in Weldsim. It combines a thermal, a mechanical and a metallurgical model. The thermal history, the welding deformations, the hardness and the microstructure distribution, the residual stresses and the distortions in the system are evaluated after a welding simulation. Through the welding simulation, the effect of the welding fixtures and the welding heat input can be assessed. Result fields from the welding simulation include the yield stress varying through the heat affected zones. This result field is imported to and applied in the crash simulation. Crash simulation is carried out with the information of changes in material performance caused by the welding heat. Through a crash simulation the ability of the system to perform correct deformation and fracture modes is verified.
Berichte der Organisationen zum Thema "AFEA"
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Ward, B. C., und L. E. Jackson. Surficial geology, Afe Creek, Yukon Territory. Natural Resources Canada/ESS/Scientific and Technical Publishing Services, 1993. http://dx.doi.org/10.4095/193345.
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Brady, Michael P., Yukinori Yamamoto, Govindarajan Muralidharan, Hiram Rogers und Bruce A. Pint. Deployment of Alumina Forming Austenitic (AFA) Stainless Steel. Office of Scientific and Technical Information (OSTI), Oktober 2013. http://dx.doi.org/10.2172/1097493.
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Schunk, Robert W. USU Gauss-Markov Model: High Resolution Regional Capability and Support for AFWA. Fort Belvoir, VA: Defense Technical Information Center, September 2006. http://dx.doi.org/10.21236/ada613100.
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LeGrand, Sandra, Christopher Polashenski, Theodore Letcher, Glenn Creighton, Steven Peckham und Jeffrey Cetola. The AFWA dust emission scheme for the GOCART aerosol model in WRF-Chem v3.8.1. Engineer Research and Development Center (U.S.), August 2021. http://dx.doi.org/10.21079/11681/41560.
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Airborne particles of mineral dust play a key role in Earth’s climate system and affect human activities around the globe. The numerical weather modeling community has undertaken considerable efforts to accurately forecast these dust emissions. Here, for the first time in the literature, we thoroughly describe and document the Air Force Weather Agency (AFWA) dust emission scheme for the Georgia Institute of Technology–Goddard Global Ozone Chemistry Aerosol Radiation and Transport (GOCART) aerosol model within the Weather Research and Forecasting model with chemistry (WRF-Chem) and compare it to the other dust emission schemes available in WRF-Chem. The AFWA dust emission scheme addresses some shortcomings experienced by the earlier GOCART-WRF scheme. Improved model physics are designed to better handle emission of fine dust particles by representing saltation bombardment. WRF-Chem model performance with the AFWA scheme is evaluated against observations of dust emission in southwest Asia and compared to emissions predicted by the other schemes built into the WRF-Chem GOCART model. Results highlight the relative strengths of the available schemes, indicate the reasons for disagreement, and demonstrate the need for improved soil source data.
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Griffin, Andrew, Sean Griffin, Kristofer Lasko, Megan Maloney, S. Blundell, Michael Collins und Nicole Wayant. Evaluation of automated feature extraction algorithms using high-resolution satellite imagery across a rural-urban gradient in two unique cities in developing countries. Engineer Research and Development Center (U.S.), April 2021. http://dx.doi.org/10.21079/11681/40182.
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Feature extraction algorithms are routinely leveraged to extract building footprints and road networks into vector format. When used in conjunction with high resolution remotely sensed imagery, machine learning enables the automation of such feature extraction workflows. However, many of the feature extraction algorithms currently available have not been thoroughly evaluated in a scientific manner within complex terrain such as the cities of developing countries. This report details the performance of three automated feature extraction (AFE) datasets: Ecopia, Tier 1, and Tier 2, at extracting building footprints and roads from high resolution satellite imagery as compared to manual digitization of the same areas. To avoid environmental bias, this assessment was done in two different regions of the world: Maracay, Venezuela and Niamey, Niger. High, medium, and low urban density sites are compared between regions. We quantify the accuracy of the data and time needed to correct the three AFE datasets against hand digitized reference data across ninety tiles in each city, selected by stratified random sampling. Within each tile, the reference data was compared against the three AFE datasets, both before and after analyst editing, using the accuracy assessment metrics of Intersection over Union and F1 Score for buildings and roads, as well as Average Path Length Similarity (APLS) to measure road network connectivity. It was found that of the three AFE tested, the Ecopia data most frequently outperformed the other AFE in accuracy and reduced the time needed for editing.
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Juan Estrada et al. Testing of the TriP Chip Running at 132 nsec Using a Modified AFE Board. Office of Scientific and Technical Information (OSTI), Dezember 2003. http://dx.doi.org/10.2172/820409.
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Brady, Michael P., Yukinori Yamamoto, Mario Epler und John H. Magee. CRADA No. NFE-10-02715 Assessment of AFA Stainless Steels for Tube Products in Chemical Processing and Energy Production Applications. Office of Scientific and Technical Information (OSTI), September 2011. http://dx.doi.org/10.2172/1024704.
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